28 



NA TURE 



[November 12, 1891 



stables, and the varied information given on the preven- 

 tion of disease. The reviser has scant sympathy with 

 the use of the actual cautery ; but here he is on debatable 

 ground, and, notwithstanding his strictures, we fancy 

 veterinarians will not lightly lay aside an agent which, 

 rightly or wrongly, most of them believe to be potent for 

 good. 



The illustrations form the least satisfactory portion of 

 the work. Many of them are grotesque and ludicrous to 

 the last degree, and ought to have been eliminated from 

 the present revised edition. Some, such as those in- 

 dicative of the symptoms of colic, are good, and well 

 convey their intended meaning. W. F. G. 



Handleiding tot de Kennis der Flora van Nederlandsch 

 Indie. Door Dr. J. G. Boerlage. Tweede Deel, 

 " Dicotyledones Gamopetalae." Eerste Stuk, " Inferag— 

 Heteromerae ; Caprifoliaceae — Styracaceae." (Leyden : 

 E. J. Brill, 1891.) 

 Previous parts of this work have been noticed in these 

 columns. It is more than thirty years since the last 

 part of Miquel's "Flora Indiae Batavse" appeared, a 

 work written chiefly in Latin ; but the present publica- 

 tion cannot be regarded as replacing it, or as being a 

 successor to it. So far as we have tested this " Manual," 

 it is a Dutch translation of the descriptions of the natural 

 orders and genera in Bentham and Hooker's " Genera 

 Plantarum," followed by a list of the species inhabiting 

 the Dutch Indies. Locally it may be serviceable ; but 

 what is wanted by botanists generally is a new descrip- 

 tive elaboration of the species of the region in question. 



W. B. H. 



By Sea-shore, Wood, and Moorland: Peeps at Nature. 



By Edward Step. (London : S. W. Partridge and Co., 



1891.) 

 The author of this book, under his pseudonym "James 

 Weston," published in 1886 "Stories and Pictures of 

 Birds, Beasts, and Fishes " ; and, two years later, a com- 

 panion volume, " Stories and Pictures of Animal Life." 

 Both of these vol,umes, which were very popular, are now 

 out of print. In the present work they have been 

 amalgamated, and the author has added to them some 

 brief " nature-papers " which he has contributed to various 

 periodicals. The book is intended chiefly for young 

 people, and it is so pleasantly written that children who 

 have a chance of reading it can hardly fail to find it at- 

 tractive. They will obtain from it much interesting in- 

 formation about all sorts of animals, and it will help them 

 to realize that even the most familiar objects, when 

 properly observed, may be worthy of close study. The 

 book is very carefully illustrated. 



LETTERS TO THE EDITOR. 



\The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of iiATV KB.. 

 No notice is taken of anonymous communications.'\ 



Note on the Chromosphere Spectrum. 



With the new spectroscope of the Halsted Observatory, 

 which has a 5-inch Rowland grating of 20,000 lines to the inch, 

 I have repeatedly observed of late that the bright chromosphere 

 line, Angstrom 6676 -9 (No. 2 in my catalogue of chromosphere 

 lines), is not coincident with the corresponding dark line of the 

 solar spectrum, but is less refrangible by about one-third of a 

 unit of Rowland's scale. This chromosphere line, therefore, 

 can no longer be ascribed to iron, but must be due to some 

 other substance as yet undetermined. 



I think there can be no doubt as to the non-coincidence. 

 The interval between the bright and dark lines varies to some 

 extent with circumstances, being usually less in the chromo- 



NO. I I 50, VOL. 45] 



sphere spectrum on the sun's eastern limb than on the western, 

 and it is often affected by motions in the line of sight ; but nine 

 times out of ten the want of coincidence is perfectly obvious. 



I may add that I have also obtained a considerable number of 

 photographs of the ultra-violet spectrum of the chromosphere 

 with the new instrument, and get complete confirmation of 

 almost all Mr. Hale's results. I find not only the constant 

 reversal of the H and K lines, but I have obtained, so far, five 

 of the ultra-violet series of hydrogen lines ; the first of them 

 being the well-known " companion " of H (first visually observed 

 by myself in 1880), and the other four in their regular succession 

 above it. 



The only point in which my plates fail to confirm Mr. Hale's 

 is that I have not yet succeeded in catching the duplicity of the 

 hydrogen a (3889). Several of his plates show at this point two 

 lines near together ; none of mine do so, and I conclude that the 

 companion line makes its appearance only rarely. I first 

 observed this line visually in 1883 [American Jottrnal of Sciettce, 

 November 1883), and it has since been often seen here by my 

 as istant, Mr. Reed, as well as by myself. 



Of course the opinion is no longer tenable that H and K can 

 be due to hydrogen, since the measures clearly show that the 

 companion to H belongs to the hydrogen series. But I am 

 still sceptical whether they are due to calcium, at least in its 

 terrestrial condition. C. A. Young. 



Princeton, NJ., U.S., October 20. 



Formation of a Temporary Cyst in the Fresh-water 

 Annelid yEolosoma. 



As I am not aware that the formation of a temporary chitinous 

 cyst has been described in any Oligochsetous Annelid, the 

 following observations may be of some little interest. A few 

 days ago Mr. Latter, science master at the Charterhouse, kindly 

 forwarded to me three tubes containing a quantity of .■^olosotna 

 quaternarium. They were so abundant that every drop of 

 water, contained several specimens ; in the water I found also a 

 still larger number of spherical bodies, which proved to be cysts, 

 each completely filled by a single worm coiled once upon itself. 

 The cysts were perfectly colourless and transparent, and very 

 thin-walled ; one cyst was found empty, and had been ruptured 

 by the worm in escaping from it. Twenty-six years ago Maggi 

 {Mem. Soc, Ital. Sci. Nat., 1865) described and figured some 

 bodies, oval in form, which he believed to be the cocoons of 

 ^olosoma ; embryos were found in these cocoons in different 

 stages of development. Prof. Vejdovsky {Entwickelungsgesch. 

 Unters., Heft i, Prag, 1888) suggested the possibility that these 

 bodies were really cysts ; my own examination of what are, I 

 think, undoubtedly cysts in Aiolosoma leads me to agree with 

 Vejdovsky's suggested interpretation of Maggi's figures. If the 

 structures which I describe here are really cocoons, their form 

 differs from that of the cocoons of all other Oligochseta, in being 

 spherical and without a narrow process at either pole ; more- 

 over, it is — on the hypothesis that they are cocoons — a remarkable 

 coincidence that they should a// contain completely adult worms ; 

 finally, and this is of course conclusive, the intestinal tract of 

 the worms contained vegetable detritus. The cysts, as I believe 

 them to be, are of about the size of a Volvox globator. In this 

 encysted condition the worms might perhaps be easily trans- 

 ported from place to place ; I have found that they survived the 

 evaporation of the surrounding water upon a glass slide for a 

 considerable period ; the worms were in continual movement 

 within their cysts, so that it was quite easy to be sure that they 

 were alive. Now this very species has a wide distribution, 

 which may perhaps be partially accounted for by this habit of 

 encystment ; with regard to other fresh-water Annelids which 

 have a wide range, such as Tubifex, it is possible that birds may 

 inadvertently transport the cocoons from country to country. It 

 is not known yet whciher ^olosojna forms a cocoon, though it is 

 probable, as the worm develops a clitellum. But sexual maturity 

 appears to be a comparatively rare occurrence in ALolosoma ; 

 very few observers appear to have seen the sexually mature 

 worms. If this is so, the encystment of the worm may take the 

 place of one of the secondary uses of the cocoon — namely, to aid 

 in the diffusion of the species. Frank E. Beddard. 



Polytechnics and Recreation. 

 In Mr. Oliver Dawson's article on Polytechnics in your 

 issue of the 8th inst. (vol. xliv., p, 547) he says: "although 



